Question

Why do a person uses a bi-focal lens?

Answer 1

As we know, bifocal glasses are usually used by people with presbyopia. In fact, they are also used by people who need to vision correction in two distance. Though it is wired to find some kids wearing bifocal eyeglasses, they have the effect to reduce the amount of eye strain during close work. And kids wearing mild prescription lenses for presbyopia can help them prevent myopia.

Answer 2

Bifocals are eyeglasses with two distinctoptical powers. Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia,hyperopia, and/or astigmatism.Bifocals can cause headaches and even dizziness in some users. Acclimation to the small field of view offered by the reading segment of bifocals can take some time, as the user learns to move either the head or the reading material rather than the eyes.Computer monitors are generally placed directly in front of users and can lead to muscle fatigue due to the unusual straight and constant movement of the head. This trouble is mitigated by the use of trifocal lenses or by the use of monofocal lenses for computer users